Silicon solar cell process development, fabrication and analyss. Third quarterly report, April-June 1979

Abstract

Solar cells have been constructed from various unconventional silicon materials. These cells have been made using conventional aerospace methods. Cells were fabricated by a baseline process and, in some cases, by processes selected to optimize performance of the matrerial. All cells, following fabrication, have been measured on the Spectrolab Solar Simulator at Air Mass Zero and 28/sup 0/C. Conversion efficiencies are based upon total device area. Maximum conversion efficiencies by either baseline or optimized processes were 10.5% for Wacker Silso, 12.0% (BSF) for Westinghouse, Web, 7.2% for Motorola RTR (Baseline), 9.8% for Mobil-Tyco EFG (RF) (Baseline), 11% for Crystal Systems HEM (Baseline), and 11.8% (Baseline) for Hamco continuous CZ material. Most of the silicon materials studied presented few, if any, difficulties in handling during processing and testing. The one exception to this has been the EFG ribbon materials. These wafers were unusually susceptible to fracture during both processing and testing.